Combination out-of-balance and safety spin switch



Jan. 4, 1966 R. L. CONRATH 3,227,835

COMBINATION OUT-OF-BALANCE AND SAFETY SPIN SWITCH Filed Oct. 6, 1964 3 Sheets-Sheet l 2 F 16.! f 2 [5 I6 IN VEN TOR RICHARD CONRA TH ATTY.

R. L. CONRATH Jan. 4, 1966 COMBINATION OUT-OF-BALANCE AND SAFETY SPIN SWITCH 3 Sheets-Sheet 2 Filed Oct. 6, 1964 INVENTOR RICHARD CONRATH ATTY.

Jan. 4, 1966 R. L. CONRATH 3,227,835

COMBINATION OUT-OF-BALANCE AND SAFETY SPIN SWITCH 3 Sheets-Sheet 5 Filed Oct. 6. 1964 8-9 IHII H I INVENTOR RICHARD CONRATH ATTY.

United States Patent 3 227,835 COMBINATION ()UT-bF-BALANCE AND SAFETY SPIN SWITCH Richard L. Conrath, Herrin, IlL, assignor to Borg-Warner Corporation, Chicago, 1th, a corporation of Illinois Filed Oct. 6, 1964, Ser. No. 401,887 4 Claims. (Cl. ZOO-61.45)

The present invention relates to centrifuging devices, for example, home laundry units and dishwashers, and more particularly to an improved safety switch for such devices.

Though the art shows switches responsive to opening of an access lid or to gyration of an article container to automatically deenergize a power mechanism in centrifuging devices, there are problems which are not solved by the switches known in the art. First, for the switches to be reliable, they must have positively operating mechanism responsive to the least movement of either an access lid or an article container beyond a predetermined limit. In some washers, for example, an access lid can be opened sufficiently for a child to slip its hand into the tub assembly without the door sensing switch being operated.

Furthermore, in order to eliminate costly adjustment or reconstruction to install the switch on different appliance units, it is necessary that the sensing or input mechanism be easily coupled to structure as the access door or gyrating article container in different appliances. In addition, the switch assembly must be simply operable and not require manual reset by the housewife once it has been operated, but instead is automatically reset at the proper time.

Accordingly, it is an object of the present invention to provide an improved safety switch for use in centrifuging units, for example, appliances such as laundry or dishwashing machines, which is sensitive by responding to precisely defined limits of movement of operative struc tures in the units such as access doors or article containers.

Along this line, it is a more detailed object to provide a safety switch of the above type which is automatically reset upon operation of the access door by the housewife and is versatile in that it can be installed in different standard domestic appliances with minor adjustment.

It is an overall object of the present invention to provide a safety switch which is inexpensive to manufacture and is foolproof in operation While at the same time providing a high degree of safety by disabling the power to the moving parts of the appliance immediately upon excessive gyration of an article container or opening of a door permitting access to spinning or rotating structure of the machine.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIGURE 1 is an elevation of an automatic washer partially in section embodying the present invention;

FIGURE 2 is a plan view of a combination lid position sensing and container unbalance sensing switch;

FIGURE 3 is a section taken along 33 in FIG. 2;

FIGURE 4 is an elevation as viewed from 44 in FIG. 3;

FIGURE 5 is an enlarged section of the switch of FIG. 3 showing the latter responding to an open access door; and

FIGURE 6 is an enlarged section elevation of the switch of FIG. 3 showing the latter responding to rotation of an unbalanced container.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment.

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On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included in the spirit and scope of the invention as defined by the appended claims.

Referring more particularly to the drawings, FIG. 1 is an elevation of an automatic washer 10 having an outer box-like cabinet 11 enclosing a vertically positioned tub 12 and basket 14 coaxially mounted about a central axis 15. The washing machine is described in detail in copending US. Patent Application of Carl J. Kneer on Automatic Washer, Serial No. 371,245, filed June 1, 1964. Positioned at the top of the cabinet and overlying the respective top openings of the tub and basket, is a cover or access door 16. The latter is hinged along one edge 18. Disposed to one side of the cabinet 11 and adjacent a tub top rim 19 and a door lower surface 20 is a switch assembly 21.

Though a specific centrifuging device has been described in introducing the invention, it is understood that other devices different appliances, for example dishwashers, as well as washing machines of different construction, for example, ones with a horizontal operating axes rather than a vertical axes, can use the switch assembly 21.

In accordance with the present invention, the improved switch assembly 21 is provided with respective input members 22, 23 for positively sensing, within precise limits, gyration of the tub 12 and opening and closing of the door 16. As herein illustrated, the switch assembly 21 is compactly carried by a frame 25 presently formed of a single piece of sheet metal and including a side mounting wall 26 and integral transversely extending top and bottom support plates 27, 28, respectively. Supported on the top plate is a switch 29 having a pair of terminals 30, 31 adapted to be connected into the power circuit of the automatic washer 10 to control operation of the latter. The switch can be of any standard type having electrical components therein operative to respectively open or close the circuit between terminals 30, 31. To effect operation of the switch, actuatable means are provided, herein shown as an engageable spring biased plunger 32 positioned on the left side of the switch as viewed in FIGS. 2, 3.

For operating the switch actuatable means 32, a suitable actuator 33 is provided. In the present instance the actuator 33 has a generally L-shaped cross section with a body 33a and a transversely extending integral wall 33b, and is supported on the frame 25 for both pivotable and slidable movement. To this end, a pin 34 having a head 34a at one end is inserted through a slot 35 in the frame side wall 26, and is then joined with the actuator body 33a by insertion of an opposite pin end 34b in a suitable receiving opening. The actuator and pin are fastened together by upsetting pin end 34b to form a rivet type joint. The distance between the head 34a and the actuator 33 after the end 34b has been upset is greater than the thickness of frame side wall 26, therefore, permitting relative movement. The head 34a is of suificient diameter to prevent the pin from slipping through the slot For sensing gyrational movements of the tub 12 within precise limits, the first input member 22, here shown as a bell-crank shaped trip lever, is pivotally carried on a depending leg 40 integral with the side wall 26 and extending below bottom plate 28. The trip lever includes a depending finger 41 positioned adjacent the tub top rim 13 and an integral extending leg 42 positioned for coupling with the switch acuator 33. As best shown in FIGS. 2 and 3, the trip lever leg 42 is provided with a catch 43, in the present instance a notch, for engaging with an edge 44 of the actuator transverse wall 33b. The actuator 33 is comprised of respective upper and lower portions 45, 46 extending respectively above and below the pin and slot support. The catch 43 is engaged with the lower portion 46 of the switch actuator and, in the illustrative embodiment, the upper portion 45 is coupled to the extending leg 42 by a biasing means 50. In the present instance, the latter takes the form of a spring suitably connected at one end 50a to a part of leg 42 extending beyond the notch 43, and at an opposite end Stlb to the switch actuator upper portion 45 so as to bias the trip lever 22 and the actuator 33 toward each other.

As a feature of the present invention, the switch actuator is operated positively and quickly in a snap type action subsequent to pivoting of the first trip lever, thereby effecting foolproof operation of the switch. To accomplish this result, in the present instance, the actuator lower portion edge 44, engageable with notch 43, is formed with an inclined lip to permit quick disengagement of the actuator and catch after the first trip l-ever has been pivoted through a predetermined angle. The catch 43 is located forward of the pin and slot support for the actuator while the latter is positioned in a first orientation relative to the bell-crank shaped trip lever 22. Accordingly, when the catch releases in response to pivoting of the trip lever, the spring 50 effects a snap movement of the actuator edge 44 away from notch 43 and positively engages switch plunger 32.

The second input means 23 is shaped and supported for responding to open and closing of the access door 16 to effect operation of the switch actuator 33. Presently, the input means 23 takes the form of a second trip lever movable between extended and retracted positions in response to opening and closing of access door 16. The trip lever includes a body portion 52, supported for pivotal movement by a pin 53 mounted in frame side wall 26, and an integral extensible finger 54, the latter being adapted to sense the position of the bottom of the door 16.

The second trip lever 23 is coupled to switch actuator 33 by a member 56. At one end 56a the link member 56 is joined to the trip lever body portion 52 by a pin 57 permitting relative pivotal movement, and at an opposite end 56b the link member has an opening for receiving actuator support pin 34, and is installed between the actuator body 33:: and frame slide wall 26.

The trip lever finger 54 is arcuately-shaped and the pivotal support pin 53 is positioned above the link member connecting pin 57 so that up and down movement of finger is transmitted as lateral movement of the link member 56. It is advantageous, for example, in sensing opening and closing of an access door to have an input member positively responsive to slight outward movements of the door. This is because the input or sensing member 22 can be positioned opposite the hinged edge of the door and adjacent that portion of the door which travels the furthest during opening and closing. Accordingly, a relative short distance movement of the door 16 toward the open position not even sulficient to permit a child to insert its hand, is sensed by finger 54 as it snaps out.

Means are provided for biasing the second trip lever 23 toward its extended position with the follower finger 54 projecting outwardly. In the present instance the biasing means takes the form of a spring 59 mounted in a generally parallel disposition relative to, and outside of the frame side wall 26. The spring is connected at its respective opposite ends to a frame anchor member 60 and a groove 61 in the pin head 34a. As is best shown in FIG. 2, the spring 59 acts to bias the actuator 33 toward the switch actuatable means 32. Accordingly, when the door is opened and the finger 54 is permitted to project outwardly, the spring 59 acts through link member 56 to pivot second trip lever 23. At the same time a transverse sliding force is applied to switch actuator 33 through pin 34. Since the lower portion 46 of the actua tor is not permitted to slide because of engagement with catch 43, the actuator is pivoted and the upper portion 45 is brought into engagement with the switch actuatable means to operate the switch. Closing of the door pivots the trip lever 23 so that the link member 56 transmits a force to pin 34, in opposition to that of the biasing spring 53, to force actuator 33 away from the switch engageable means, thereby returning the mechanism to its normal or unactuated position.

Explaining operation of the washer using the present improved safety switch, it is first assumed that the basket 14 contains a non-uniformally distributed load of clothes, and that it is rotated during a washer spin cycle. As the basket begins to spin, it will move transversely relative to the vertical axes 1.5 and, as a result, the tub 12 is gyrated so that the tub top rim 19 moves transversely beyond a predetermined limit. As a result, the tub top rim 19 will contact the depending finger 41 of the first input member or trip lever 22 and pivot the latter in a clockwise direction as viewed in FIG. 6. The trip lever and switch actuator are initially positioned in a first orientation, in which the switch 29 is unactuated. The result of pivoting the trip lever 22 is that the switch actuator 33 and the trip lever 22 are positioned in a second orientation in which a lower lip 44 of the switch actuator transverse wall 33b is cammed free of the notch 43. The spring 5G pulled down by trip lever leg 42 applies a clockwise pivotal movemerit to the switch actuator upper portion 45 to bring it into engagment with the switch actuatable means 32. As has been explained, the lip 44 and the notch 43 are constructed to cooperate in permitting the actuator lower edge to ride up onto a top edge 42a of trip lever leg 42, and thereby maintain the switch 29 actuated even after the tub gyration has stopped. This is because the leg top edge 42a is shaped so that the lip 44 engages it at an angle providing a friction force therebetween which prevents automatic return of the actuator into engagement with the catch. Of course, the friction holding force can be effected in other ways, for example by roughing the surface 42a.

The movement required to operate the switch actuator is adjustable by selecting a spring 59 having a predetermined spring constant and constructing the catch. 43 and the actuator lower edge 44 with characteristics permitting either difficult or easy release. In the present instance, the engagement of the switch actuatable means 32 by the switch actuator 33, i.e. the actuator and first input member positioned in a second orientation, results in opening the circuit between switch terminals 30, 31. By reference to the aforementioned copending patent application, it is understandable to one skilled in the art, the position in the circuit the switch 29 should take in order to effect disabling of washer operation in response to excessive gyrations by the tub 12.

At this point in the operation of the washer, the machine having stopped, the housewife lifts the door 16 and rearranges the load so that it is more nearly balanced. Upon opening of the door 16, the second trip lever 23 is pivoted by the action of biasing spring 59. Also, in response to the action of spring 59, the switch actuator 33 is slid to the right as viewed in FIG. 6. The force produced by spring 59 is sufficient to overcome the bias of spring 50 so as to reengage the edge or lip 44 of the switch actuator with the notch 43 in leg 42 of the trip lever. Thus, when the housewife returns the door to its closed position, and the extending finger 54 of the second trip lever is pressed down by the door lower surface 20, thereby pivoting the trip lever 23, a lateral movement is transmitted to the switch actuator 23 by the link member 56. Because the switch actuator is held at its bottom end by the notch 43, the lateral movement results in pivotal movement of the actuator (to the left in FIGS. 2 and 3) thereby disengaging the actuator upper portion 45 from the switch plunger 32. Thus, the switch actuator and the first trip lever are automatically reset in response to opening and closing of the door to their first orientation.

The switch 29 is also actuated in response to opening and closing of the door 16. Pivotal movement of the second input member or trip lever 23, sensing the position of door 16, is transmitted by link 56 into pivotal movement of the switch actuator to respectively actuate or de-actuate the switch plunger 32. Opening of the door effects pivoting of the switch actuator 33 so that the actuator upper portion 45 pushes the plunger 32 and opens the circuit between switch terminals 30 and 31. On the other hand, closing of the door effects movement of the link member 56 to pivot the switch actuator 33, against the bias of spring 59 to disengage the switch actuator upper portion 45 from the plunger 32, and thereby close the circuit between terminals 30, 31.

It is clear from the foregoing that the novel switch structure here shown is compact and the simply operable input members 22, 23 can be easily adjusted for installation in different machines which require sensing of both an access door and a gyrating container such as a washer tub. Though in the present instance, a particular plunger switch has been described and a particular mechanism for actuating it, other switches, for example of the proximity type, may also be adapted for use with the required simple changes in structure of the actuating means, these changes being easily made by one skilled in the art following the teachings of the present invention. The advantages of a snap action operation of the switch makes the present switch operating assembly particularly useful where immediate stopping of operating mechanism is necessary if sensed conditions have proceeded beyond a predetermined limit. The biasing effected by the springs 5t), 59 in the present switch operating assembly along with the particular pivotal movement and orientation of actuatable members provides this desired result.

What is claimed is:

Ti. In a washer having an outer cabinet for enclosing operative structure including an electrical circuit for providing power to said operative structure, the combination comprising a tub subject to gyrations during predetermined operations of the washer, a door hingedly supported by the cabinet and selectively operative to respectively permit and block access to said tub, a switch assembly supported within said cabinet adjacent said tub and said door and responsive both to gyrations by said tub beyond a predetermined limit and to opening of said door to deenergize the washer electrical system, said switch assembly characterized by a frame, a switch supported on said frame and effective to open and close said electrical circuit, actuatable means for operating said switch, an actuator supported by said frame for pivotable and slidable movement and being selectively coupled to said switch actuatable means to operate the same, a first input member pivotally supported by said frame adjacent said tub to respond to gyrational movements there of, first means biasing said actuator and said first input member toward each other, a releasable catch cooperating with said first biasing means to position said actuator and said first input member in a predetermined first relative orientation, said first input member responsive to gyrational movement of said tub beyond a predetermined limit to pivot said first member and release said catch to position said actuator and said first member in a predetermined second orientation, said actuator in said second orientation effecting operation of said switch actuatable means, a second input member coupled to said actuator and supported by said frame for movement between respective retracted and extended positions and a second means biasing said second input member toward the extended position thereof, said cover in said access blocking position operating said second input member to said retracted position, said second means effective in said extended position to move said actuator to effect operation of said switch actuatable means and operative in response to movement thereof from said extended position to said retracted position corresponding to opening and closing of said door to effect re-engagement of said catch and return of said actuator to said first orientation position.

2. The combination comprising a frame, a switch supported by said frame and having engagable means for operating said switch. between respective first and second positions, said switch normally in said first position, a switch actuator supported by said frame for pivotable and slidable movement and having first and second portions respectively extending on either side of said support, said actuator first portion responsive to said actuator movement to operate said switch engageable means, a first trip lever pivotably supported on said frame and coupled to said actuator second portion for moving said actuator and operating said switch engageable means, said first trip lever having a catch engageabie with said actuator second portion, a first spring biasing said actuator first portion about said actuator support toward said switch engageable means and normally mainta ning said second actuator portion engaged with said catch, said first trip lever responsive to predetermined angular movement to release said actuator second portion from said catch and permit engagement of said actuator first portion with said switch engageable means to actuate said switch to said second position, a second trip lever coupled to said switch actuator and selectively movable between respective retracted and extend-ed positions to effect operation of said switch engageable means and move said switch between respective first and second positions, said actuator second portion remaining disengaged from said catch and cammed by said first trip lever to maintain said actuator first portion and said switch engageable means coupled to hold said switch in said second position, a second spring biasing said actuator first portion toward said switch engageable means and maintaining said second trip lever in an extended position, said second trip lever responsive to the bias of said second spring to operate said switch actuator and re-engage said actuator second portion with said catch.

3. The combination of claim 2 wherein said catch is a notch on said first trip lever for engaging with said switch actuator second portion said notch positioned forward of said actuator pivotable support to permit snap action release of said actuator in response to pivoting of said first trip lever.

4. The combination of claim 2 wherein said second trip lever is formed with an extending generally arcuate finger and is connected to said switch actuator by a link member, said trip lever pivotally supported to one side of said connection to said link member to permit sensing of an up and down movement and transmitting such movement as both pivotable and slidable movement to said switch actuator.

References Cited by the Examiner UNITED STATES PATENTS 2,882,360 4/1959 Sisson 200-61 3,145,818 8/1964 Stelli 210-144 3,149,212 9/1964 Smith 2006 l References Cited by the Applicant UNITED STATES PATENTS 2,612,766 10/1952 Smith et al. 2,878,937 3/1959 Worst. 2,957,959 lO/l960 Mellinger.

3,051,313 8/1962 Stelli.

BERNARD A. GILHEANY, Primary Examiner.

J. J. BAKER, Assistant Examiner. 

1. IN A WASHER HAVING AN OUTER CABINET FOR ENCLOSING OPERATIVE STRUCTURE INCLUDING AN ELECTRICAL CIRCUIT FOR PROVIDING POWER TO SAID OPERATIVE STRUCTURE, THE COMBINATION COMPRISING A TUB SUBJECT TO GYRATIONS DURING PREDETERMINED OPERATIONS OF THE WASHER, A DOOR HINGEDLY SUPPORTED BY THE CABINET AND SELECTIVELY OPERATIVE TO RESPECTIVELY PERMIT AND BLOCK ACCESS TO SAID TUB, A SWITCH ASSEMBLY SUPPORTED WITHIN SAID CABINET ADJACENT SAID TUB AND SAID DOOR AND RESPONSIVE BOTH TO GYRATIONS BY SAID TUB BEYOND A PREDETERMINED LIMIT AND TO OPENING OF SAID DOOR TO DEENERGIZE THE WASHER ELECTRICALD SYSTEM, SAID SWITCH ASSEMBLY CHARACTERIZED BY A FRAME, A SWITCH SUPPORTED ON SAID FRAME AND EFFECTIVE TO OPEN AND CLOSE SAID ELECTRICAL CIRCUIT, ACTUATABLE MEANS FOR OPERATING SAID SWITCH, AN ACTUATOR SUPPORTED BY SAID FRAME FOR PIVOTABLE AND SLIDABLE MOVEMENT AND BEING SELECTIVELY COUPLED TO SAID SWITCH ACTUATABLE MEANS TO OPERATE THE SAME, A FIRST INPUT MEMBER PIVOTALLY SUPPORTED BY SAID FRAME ADJACENT SAID TUB TO RESPOND TO GYRATIONAL MOVEMENTS THEREOF, FIRST MEANS BIASING SAID ACTUATOR AND SAID FIRST INPUT MEMBER TOWARD EACH OTHER, A RELEASABLE CATCH COOPERATING WITH SAID FIRST BIASING MEANS TO POSITION SAID ACTUATOR AND SAID FIRST INPUT MEMBER IN A PREDETERMINED FIRST RELATIVE ORIENTATION, SAID FIRST INPUT MEMBER RESPONSIVE TO GYRATIONAL MOVEMENT OF SAID TUB BEYOND A PREDETERMINED LIMIT TO PIVOT SAID FIRST MEMBER AND RELEASE SAID CATCH TO POSITION SAID ACTUATOR AND SAID FIRST MEMBER IN A PREDETERMINED SECOND ORIENTATION, SAID ACTUATOR IN SAID SECOND ORIENTATION EFFECTING OPERATION OF SAID SWITCH ACTUATABLE MEANS, A SECOND INPUT MEMBER COUPLED TO SAID ACTUATOR AND SUPPORTED BY SAID FRAME FOR MOVEMENT BETWEEN RESPECTIVE RETRACTED AND EXTENDED POSITIONS AND A SECOND MEANS BIASING SAID SECOND INPUT MEMBER TOWARD THE EXTENDED POSITION THEREOF, SAID COVER IN SAID ACCESS BLOCKING POSITION OPERATING SAID SECOND INPUT MEMBER TO SAID RETRACTED POSITION, SAID SECOND MEANS EFFECTIVE IN SAID EXTENDED POSITION TO MOVE SAID ACTUATOR TO EFFECT OPERATION OF SAID SWITCH ACTUATABLE MEANS AND OPERATIVE IN RESPONSE TO MOVEMENT THEREOF FROM SAID EXTENDED POSITION TO SAID RETRACTED POSITION CORRESPONDING TO OPENING AND CLOSING OF SAID DOOR TO EFFECT RE-ENGAGEMENT OF SAID CATCH AND RETURN OF SAID ACTUATOR TO SAID FIRST ORIENTATION POSITION. 